William l



UNITED STATES PATENT *OFFICE.

WILLIAM L. VOELKER, or ELIZABETH, NEw JERSEY, ASsIGNon, EYMESNE ASSIGNMENTS, To THE CONSOLIDATED STERLING INoANDESoENT GAS LAMP COMPANY, OF NEW JERSEY.

Hooo, 800., FOR INCANDESCENT GAS-LIGHTS.

SPECIFICATION forming part of Letters Patent No. 562,442, dated June 23, 1896.

Application filed October 14, 1895. serial No. 565,685. (No specimens.)

To aZZ whom it may concern:

Be it known that I, WILLIAM L. V' ELKER, a citizen of the United States,and a resident of the city of Elizabeth, Union county, State of New Jersey, have invented certain new and useful Improvements in Hoods, Mantles, or Gratings for Incandescent GaS-Lights, of which the following is a specification.

This invention relates to hoods, mantles, or

IO gratings for incandescent gas-lights.

In particular, it relates to the filaments of which such hoods, mantles, or gratings are constructed, and it is the aim of this invention to produce a filament having such tensile I 5 strength that it can be readily handled by ordinary weaving or braiding machinery.

In another application which is now pending in the United States Patent Office I have mentioned a thread formed 'of a material which I have termed celluoXide, and the basis of which is celluloid, combined with such metallic oxids as are best adapted to give light by incandeseence. Such a thread may be produced by forcing the mass of celluoxide through a die, by drawing it through a die, or by rolling it through channel-rolls.

Although a thread or fiber formed by these.

means has considerable tensile strength, it

cannot safely be handled so roughly as is re- 0 quired by ordinary weaving or braiding machinery. I have, however, invented a means of greatly increasing the tensile strength of the thread. I proceed in the following manner: When the thread or fiber of celluoxide 3 5 is suificiently dry, it is covered with a thin cotton braid, or it may be covered, as some wires used in electrical Work are, by right and lefthand spiral winding. I may also run several strands of cotton yarn or other combustible fibers along with the thread or fiber of the celluoxide, and then run the cotton cover on spirally, and in this way I greatly increase the tensile strength of the thread.

The mechanical strain produced by braiding or weaving machinery is taken up by the cotton covering, which is placed on the thread in the manner just before describ'ed,'and the hood, mantle, or grating braided or woven with the thread of this characterwill when baked have loose contactjoints, while the cotton covering does not interfere with the contraction during baking, but does preserve the elasticity of the thread a long time by preventing the evaporation of the oil of cassia which was used in forming the celluoxide.

Although the joints of the hood or mantle are loose, as above explained, yet after baking the mantle will preserve its shape, for, first, after baking the filaments acquire a certain hardness and elasticity which preserves them in their original form of spirals, and, secondly, while the mantle is capable of being compressed vertically, yet when suspended from a rod at the top in the usual manner its weight opens it vertical to a cerrain degree, which determines the normal height of the mantle. Thereafter its dimensions vary only within the narrow limits of its contractions and expansions. An important result of covering the fila- 7 mentswith the case or sheath of combustible material is, as above indicated, that the filaments do not stick together at the points where they cross or interlace, but remain free. Therefore, when the case is burned out 7 5 we have a hood composed of filaments each of whichis free to expand and contract without exerting strain on the other filaments or being strained by them, and the durability of the hood is, in this manner, materially increased.

While I prefer to employ the Wrapping of combustible fibrous material with the thread of celluoxide, nevertheless I do not wish to restrict the use of the covering to such a thread; but I do intend to include the application of the Wrapping of the fibrous sub stances with threads of any suitable incandesoing material.

Now, having described my improvement, I claim as my invention- 1. A filament for incandescent gas-lights, composed of a core of celluoxide and a casing of fibrous combustible material, substantially as described.

2. A hood, mantle or grating for incandescent gas-lights woven or braided with threads which consist of a filamentary core ofiineandescing minerals covered by an envelop of fibrous combustible materials, substantially as described.

In testimony that I claim the foregoing as inyinventionI have signed myname, in presence of two Witnesses, this 9th dayof August, 1895.

VILLIAM L. VOELKER.

Witnesses BERNARD J. ISECKE, HENRY V. BROWN. 

